I am attempting to do a NeuN stain on free-floating, gelatin embedded, paraformaldehyde fixed, 50 micron,vibratome cut sections of superior cervical ganglion. I am getting a small amount of positive staining after floating the sections for two days at room temperature, but I know that staining should be prolific. I use citric acid HIER on paraffin embedded sections with the same antibody and get very good results. The only type of retrieval the I currently use on the free floating sections is to incubate them in 0.4% Triton in PBS. Is there a non-heated antigen retrieval that can be used to good effect on free floating sections? I appreciate any and all input on this matter.

You can try HIER on free floating sections. We have placed a container containing the citric acid ph 6.0 in a water bath or oven set at 90 degrees to warm. We then placed the sections in their baskets in the container for 20 minutes (I think this was the time we used). This seemed to work okay but we only did a few times, so I am not sure how well it works for all types of sections.